A083938 - OEIS

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A083938

A014486-indices of binary trees whose left and right subtree are identical.

0, 1, 6, 42, 52, 385, 414, 477, 506, 555, 4089, 4180, 4388, 4479, 4645, 5095, 5186, 5394, 5485, 5651, 5969, 6060, 6226, 6502, 47363, 47661, 48366, 48664, 49237, 50800, 51098, 51803, 52101, 52674, 53808, 54106, 54679, 55681, 59311, 59609, 60314

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OFFSET

0,3

COMMENTS

Fixed points of permutation A069770. Diagonal of A072764 (and A072766).

LINKS

Table of n, a(n) for n=0..40.

FORMULA

a(0)=0, a(n)=A072764bi(n-1, n-1).

CROSSREFS

a(n) = A080300(A083939(n)). Cf. A083940.

Sequence in context: A153243 A186885 A097253 * A292316 A329000 A329339

Adjacent sequences: A083935 A083936 A083937 * A083939 A083940 A083941

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 13 2003

STATUS

approved